Preparation of crosslinked polymers containing biomass derived materials

ABSTRACT

Processes for preparing crosslinked polymers using biomass derived materials, such as aldaric acids and derivatives, are provided. The polymers can be used as hydrogels.

FIELD OF INVENTION

The invention is directed to the preparation of novel, crosslinked polymers using biomass derived materials, such as aldaric acids and derivatives. These polymers can be used as hydrogels.

BACKGROUND

The concept of using biomass-derived materials to produce other useful products has been explored since man first used plant materials and animal fur to make clothing and tools. Biomass derived materials have also been used for centuries as adhesives, solvents, lighting materials, fuels, inks/paints/coatings, colorants, perfumes and medicines. Recently, people have begun to explore the possibility of using “refined biomass” as starting materials for chemical conversions leading to novel high value-in-use products. Over the past two decades, the cost of renewable biomass materials has decreased to a point where many are competitive with those derived from petroleum. In addition, many materials that cannot be produced simply from petroleum feedstocks are potentially available from biomass or refined biomass. Many of these unique, highly functionalized, molecules would be expected to yield products unlike any produced by current chemical processes. “Refined biomass” is purified chemical compounds derived from the first or second round of plant biomass processing. Examples of such materials include cellulose, sucrose, glucose, fructose, sorbitol, erythritol, and various vegetable oils.

A particularly useful class of refined biomass is that of aldaric acids. Aldaric acids, also known as saccharic acids, are diacids derived from naturally occurring sugars. When aldoses are exposed to strong oxidizing agents, such as nitric acid, both the aldehydic carbon atom and the carbon bearing the primary hydroxyl group are oxidized to carboxyl groups. An attractive feature of these aldaric acids includes the use of very inexpensive sugar based feedstocks, which provide low raw material costs and ultimately could provide low polymer costs if the proper oxidation processes are found. Also, the high functional density of these aldaric acids provide unique, high value opportunities, which are completely unattainable at a reasonable cost from petroleum based feed stocks.

Hydrogels (hydrated gel) are polymers that contain water-swellable, three-dimensional networks of macromolecules held together by covalent or noncovalent (e.g., ionic or hydrogen bonded) crosslinks. Upon placement in an aqueous environment, these networks swell to the extent allowed by the degree of crosslinking. They are used in many fields such as medical applications, personal care formulations, coatings, and surfactants.

U.S. Pat. No. 5,496,545 discloses crosslinked polyallylamine and polyethyleneimine. The crosslinking agents disclosed include epichlorohydrin, diepoxides, diisocyanates, α,ω-dihaloalkanes, diacrylates, bisacrylamides, succinyl chloride, and dimethyl succinate. Applicants have invented a process to prepare new crosslinked polymers that can function as hydrogels, using crosslinking moieties that could be derived from biomass sources.

SUMMARY OF THE INVENTION

One aspect of the invention is a process for preparing a crosslinked polymer, comprising contacting a crosslinking agent with a substrate polymer to form a crosslinked polymer; wherein the crosslinking agent is selected from compounds having Formulae VI, VII and VIII:

-   -   wherein L and L′ independently contain a suitable functional         group, and n=1-6, m=0-4, and p=1-4;     -   and the substrate polymer comprises:     -   a linear, branched or cyclic polymeric backbone comprising         repeat units that comprise one or more of hydrocarbylene groups,         heteroatoms, and carbonyl carbon groups;         -   wherein the hydrocarbylene groups are aliphatic or aromatic,             linear, branched, or cyclic, or combinations thereof; and     -   reactive pendant groups attached to the polymeric backbone, the         pendant groups being of the formula -G or —R-G,         -   wherein G is a nucleophile or electrophile;         -   wherein R is independently linear, cyclic, or branched             alkylene, arylene, or alkarylene groups of 1-22 carbon             atoms, optionally substituted with alkyl, aryl, hydroxy,             amino, carbonyl, ester, amide, alkoxy, nitrile or halogen,             and optionally containing —O—, —Si(ZZ′)O—, —(C═O)— or —NZ—             linkages, where Z and Z′ are independently hydrogen, alkyl,             substituted alkyl, alkaryl, substituted alkaryl, aryl, or             substituted aryl. The hydrocarbylene groups and heteroatoms             of the repeat units are optionally substituted with             substituents that comprise one or more of C₁-C₃₀             hydrocarbylene groups, heteroatoms, and carbonyl carbon             groups. The hydrocarbylene groups of the substituents are             aliphatic or aromatic, linear, branched, or cyclic, or             mixtures thereof.

Preferably the suitable functional groups contained by L and L′ are derived from an amine, hydroxyl, carboxylic acid, ester, urethane, urea, amide, or isocyanate; and G is an epoxide, isocyanate, benzylic halide, amine, acid halide, ester, or amide. Also preferably L and L′ are selected from the group consisting of optionally substituted —NHR″, —OR″, and hydrocarbylene-C(═O)OR″; and G is selected from the group consisting of —NH₂, —C(═O)Cl, —C(═O)OR″, or —C(═O)NH—R″—NH₂; wherein R″ is independently an optionally substituted hydrocarbyl or hydrocarbylene, and wherein n=2-4, m=0-1, and p=2-3. The optional substituents on R″ can be any heteroatom-containing group that does not participate directly in reactions between the substrate polymer and the crosslinking agent; i.e., the substituent is preferably not displaced during such reaction and does not form a covalent bond with the substrate polymer. Groups attached to the polymer by reaction with G can contain aza (—NZ—) or ether (—O—) linkages (e.g., G can be PEGylated).

In one embodiment of the process, less than 100% of the reactive pendant groups are derivatized to make the derivatized pendant groups substantially unreactive to the crosslinking agent, wherein the derivatization is performed either before, during or after contact of the crosslinker with the polymer substrate. “Substantially unreactive”, as used herein, means having a rate of reaction, e.g., with the crosslinking agent, of about 20% or less of the rate of reaction of an underivatized pendant group under the same conditions. Preferably the reactive pendant groups are derivatized to contain an optionally substituted aliphatic carbon chain with optional —(NZ)—, and —O— linkages, where Z is hydrogen, optionally substituted alkyl or optionally substituted aryl.

In another embodiment, the crosslinking agent is derived from an aldaric acid, aldarolactone, aldarodilactone, aldarolactone ester, aldaric acid monoester, aldaric acid diester, or aldaramide, or salts thereof, and the substrate polymer comprises polyallylamine, polyallylamine hydrochloride, branched polyethyleneimine, branched polyethyleneimine hydrochloride, poly(acryloyl chloride), poly(methacryloyl chloride), poly[N-(ω-aminoalkyl)acrylamide], polyglycosamine, carboxymethylchitosan, chitosan, chitosan hydrochloride, or derivatives or salts thereof. By “derived from” is meant that the crosslinking agent can be produced from a starting compound in about six or fewer chemical reaction steps, and retains an aldaric structure —C(═O)(CHOR)_(n)C(═O)— wherein R is H or a carbon-containing group such as alkyl.

Preferably the crosslinking agent is selected from compounds having Formulae IX, X, XI, and XII:

wherein A1 is selected from the group consisting of:

and salts thereof;

and A2 is selected from the group consisting of —NH—R₅—NH— —NH—R₅—O— and —O—R₅—O—

and salts thereof;

wherein R₅ and R₇ are independently aliphatic or aromatic hydrocarbylene groups, linear, branched or cyclic, optionally substituted, and optionally containing —O—, —Si(ZZ′)O—, —(C═O)— or —NZ— linkages, where Z and Z′ are independently hydrogen, alkyl, substituted alkyl, alkaryl, substituted alkaryl, aryl, or substituted aryl; and R₆ is hydrogen or a 1-22 carbon alkyl group.

These and other aspects of the present invention will be apparent to one skilled in the art, in view of the following description and the appended claims.

DETAILED DESCRIPTION

The following definitions may be used for the interpretation of the specification and the claims:

By hydrocarbyl is meant a straight chain, branched or cyclic arrangement of carbon atoms connected by single, double, or triple carbon-to-carbon bonds, and substituted accordingly with hydrogen atoms. Such hydrocarbyl groups can be aliphatic and/or aromatic. Examples of hydrocarbyl groups include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl, cyclopropyl, cyclobutyl, cyclopentyl, methylcyclopentyl, cyclohexyl, methylcyclohexyl, benzyl, phenyl, o-tolyl, m-tolyl, p-tolyl, xylyl, vinyl, allyl, butenyl, cyclohexenyl, cyclooctenyl, cyclooctadienyl, and butynyl. Examples of substituted hydrocarbyl groups include tolyl, chlorobenzyl, —(CH₂)—O—(CH₂)—, fluoroethyl, p-(CH₃S)C₆H₅, 2-methoxypropyl, and (CH₃)₃SiCH₂.

“Alkyl” means a saturated hydrocarbyl group. Common examples of such alkyl groups include methyl, ethyl, propyl, isopropyl, butyl, s-butyl, isobutyl, pentyl, neopentyl, hexyl, heptyl, isoheptyl, 2-ethylhexyl, cyclohexyl and octyl.

“Aryl” means a group defined as a monovalent radical formed conceptually by removal of a hydrogen atom from a hydrocarbon that is structurally composed entirely of one or more benzene rings. Common examples of such hydrocarbons include benzene, biphenyl, terphenyl, naphthalene, phenyl naphthalene, and naphthylbenzene.

“Alkaryl” means an alkylated aryl group; that is, an aryl group as defined above that is substituted with an alkyl group.

By “hydrocarbylene,” “alkylene,” “arylene,” or “alkarylene” is meant the divalent form of the corresponding group.

“Substituted” and “substituent” mean that a group is substituted and contains one or more substituent groups, or “substituents,” that do not cause the compound to be unstable or unsuitable for the use or reaction intended. Unless otherwise specified herein, when a group is stated to be “substituted” or “optionally substituted,” substituent groups that can be present include carboxyl, carboxamido (including primary, secondary or tertiary carboxamido), acylamino, alkoxycarbonylamino, sulfonylamino, cyano, alkoxy, alkoxycarbonyl, acyloxy, fluoro, chloro, bromo, iodo, amino (including primary, secondary and tertiary amino), hydroxy, alkenyl, oxo, imino, hydroxyimino, hydrocarbyloxyimino, wherein the hydrocarbyl group can be aliphatic, aryl or a combination of the two, trihydrocarbylsilyl, wherein each hydrocarbyl group can be independently alkyl or aryl, trihydrocarbylsiloxy, wherein each hydrocarbyl group can be independently alkyl or aryl, nitro, nitroso, hydrocarbylthio, wherein the hydrocarbyl group can be aliphatic, aryl or a combination of the two, hydrocarbylsulfonyl, wherein the hydrocarbyl group can be aliphatic, aryl or a combination of the two, hydrocarbylsulfinyl, wherein the hydrocarbyl group can be aliphatic, aryl or a combination of the two, hydrocarbyloxysulfonyl, wherein the hydrocarbyl group can be aliphatic, aryl or a combination of the two, sulfonamido (including primary, secondary and tertiary sulfonamido), sulfonyl, dihydrocarbylphosphino, wherein each hydrocarbyl group can be independently alkyl or aryl, dihydrocarbyloxyphosphino, wherein each hydrocarbyl group can be independently alkyl or aryl, hydrocarbylphosphonyl, wherein the hydrocarbyl group can be aliphatic, aryl or a combination of the two, hydrocarbyloxyphosphonyl, wherein the hydrocarbyl group can be aliphatic, aryl or a combination of the two, phosphonamido (including primary, secondary and tertiary phosphonamido), and salts of the aforementioned.

Aldaric acids are diacids derived from naturally occurring sugars. When aldoses are exposed to strong oxidizing agents, such as nitric acid, both the aldehydic carbon atom and the carbon bearing the primary hydroxyl group are oxidized to carboxyl groups. This family of diacids is known as aldaric acids (or saccharic acids). An aldarolactone has one carboxylic acid lactonized; the aldarodilactone has both lactonized. As illustration, the aldaric acid derivatives starting from D-glucose are shown below.

Any stereoisomer or mixture of stereoisomers can be used in the processes of the present inventions. The aldaric acid derivative can be glucaric acid or galactaric acid, or their derivatives such as glucarolactone, glucarodilactone, galactarolactone, and dimethyl galactarate.

The invention is directed to processes for preparing crosslinked polymers comprising contacting a crosslinking agent with a substrate polymer to form a crosslinked polymer; wherein the crosslinking agent is one or more of Formulae VI, VII and VIII:

and n=1-6, m=0-4, and p=1-4. Preferably n=2-4, m=0-1, and p=2-3.

The substrate polymer used in the instant process comprises a linear, branched or cyclic polymeric backbone. The backbone contains repeat units that comprise one or more of hydrocarbylene groups, heteroatoms, and carbonyl carbon groups. The hydrocarbylene groups are aliphatic or aromatic, linear, branched, or cyclic, or combinations thereof. The hydrocarbylene groups and heteroatoms of the repeat units are optionally substituted with substituents that comprise one or more of C₁-C₃₀ hydrocarbylene groups, heteroatoms, and carbonyl carbon groups, wherein the hydrocarbylene groups of the substituents are aliphatic or aromatic, linear, branched, or cyclic, or combinations thereof.

The polymeric backbone used in the process can contain —NZ—, —N⁺ZZ′—, —O—, —C(═O)NZ—, —C(═O)O—, —C(═O)—, —OC(═O)O—, —OC(═O)NZ—, —NZC(═O)NZ′—, or —SiZZ′O— linkages, where Z and Z′ are independently hydrogen, alkyl, substituted alkyl, aryl, or substituted aryl.

The substituents on the repeat units are preferably one or more of —X, —O(Z), —N(ZZ′)—, —N⁺(ZZ′Z″), —C(═O)OZ, —C(═O)X, —C(═O)NZZ′, —C═N═O—, —O—, —N(Z)—, —N⁺(ZZ′)—, —C(═O)N(Z)—, —C(═O)O—, —C(═O)—, —OC(═O)O—, —OC(═O)N(Z)—, —N(Z)C(═O)N(Z′)—, —C(═O)NH(CH₂)_(p)NH₂, —Si(ZZ′)O—, —(OCH₂CH₂)_(m)OH, or —(OSi(ZZ′))_(n)OH, or salts thereof, where X is a halogen, Z, Z′, and Z″ are independently hydrogen, C₁-C₂₂ optionally substituted alkyl, or C₁-C₂₂ optionally substituted aryl, and where m is 1 to 50, n is 1 to 100, and p is 1 to 12. More preferably, the substituents comprise one or more of C₁-C₂₂ aminoalkyl groups, optionally substituted with alkyl or aldaroyl, or a salt thereof. The repeat units preferably comprise aliphatic hydrocarbylene groups with substituents comprising one or more of aminoalkyl groups, —C(═O)OZ, —C(═O)X, —C(═O)NZZ′, or —C(═O)NH(CH₂)_(n)NH₂, or salts thereof, where X is halogen, Z and Z′ are independently hydrogen, C₁-C₂₂ alkyl, substituted alkyl, aryl, or substituted aryl, and n=1-12.

The repeat unit can be an azahydrocarbylene or a salt thereof with one or more terminal amino groups or salts thereof as substituents on the N of the azahydrocarbylene repeat unit.

The substrate can also comprise polyallylamine, polyallylamine hydrochloride, branched polyethyleneimine, branched polyethyleneimine hydrochloride, poly(acryloyl chloride), poly(methacryloyl chloride), poly[N-(ω-aminoalkyl)acrylamide], polyglycosamine, carboxymethylchitosan, chitosan, chitosan hydrochloride, or derivatives or salts thereof.

Attached to the polymeric backbone are reactive pendant groups of the formula -G or —R-G; where G is a nucleophile or electrophile; and where R is independently linear, cyclic, or branched alkylene, arylene, or alkarylene groups of 1-22 carbon atoms, optionally substituted with alkyl, aryl, hydroxy, amino, carbonyl, ester, amide, alkoxy, nitrile or halogen, and optionally containing —O—, —Si(ZZ′)O—, —(C═O)— or —NZ— linkages, where Z and Z′ are independently hydrogen, alkyl, substituted alkyl, alkaryl, substituted alkaryl, aryl, or substituted aryl.

The terms “electrophile” and “nucleophile” are well known to those skilled in the art, and can be broadly defined as reactive chemical moieties that act as electron acceptors or electron donors. Preferred is where G is an epoxide, isocyanate, benzylic halide, amine, acid halide, ester, or amide; more preferred is where G is —NH₂, —C(═O)Cl, —C(═O)OR″ or —C(═O)NH—R″—NH₂; wherein R″ is independently hydrogen or an optionally substituted hydrocarbyl or hydrocarbylene. Most preferably G is —NH₂.

L and L′ are defined as containing a suitable functional group. A suitable functional group is herein defined as a functional group that readily forms a covalent bond with the reactive pendant group. The specific functional group employed will depend upon the particular synthetic method used to make the crosslinked polymer. It may contain heteroatoms such as O, N, S, and/or is derived from a functional group such as an amine, hydroxyl, carboxylic acid, ester, urethane, urea, amide, or isocyanate. Particularly useful functional groups are those that contain a —NH— group, a —C(═O)O— group, a —O— group, or salts thereof. Preferably, the suitable functional group is derived from an amine, hydroxyl, carboxylic acid, ester, urethane, urea, amide, or isocyanate. More preferably L and L′ are independently selected from the group consisting of —Y—R, wherein Y is O, NH, or S and R is alkyl, substituted alkyl, alkaryl, substituted alkaryl, aryl, or substituted aryl. Also more preferably L and L′ are independently selected from the group consisting of optionally substituted —NHR″, —OR″, and hydrocarbylene-C(═O)OR″; wherein R″ is an optionally substituted hydrocarbylene, and wherein n=2-4, m=0-1, and p=2-3.

As illustration, a crosslinker that is capped with a carboxylic acid as the suitable functional group would be expected to react readily with available amine pendant groups on the polymeric backbone. A crosslinker end-capped with a hydroxyl group or an amine as a functional group would not be expected to react with the pendant amine functionality of the polymeric backbone. However, if the subject polymer backbone had a carboxylic acid or an isocyanate as pendant functionality, then a crosslinker capped with an amine or a hydroxyl functional group could react with the pendant group of the polymeric backbone.

In another embodiment, less than 100%, preferably about 50% or less, and more preferably about 20% or less, of the reactive pendant groups are derivatized to make the derivatized pendant groups unreactive to the crosslinking agent. The derivatization can be performed by contacting the reactive pendant groups with a derivatizing reagent before, during or after contact of the crosslinker with the polymer substrate. Preferably, the reactive pendant groups are derivatized before the contact of the crosslinker with the polymer substrate. The reactive pendant groups can be derivatized to contain an optionally substituted aliphatic carbon chain with optional —(NZ)—, and —O— linkages, where Z is hydrogen, optionally substituted alkyl or optionally substituted aryl. Preferably, the reactive pendant groups are derivatized to contain a linear or branched alkyl group of 1-22 carbon atoms, optionally substituted with —O— linkages, and optionally substituted with —NH₂, halogen, hydroxyl, or carbonyl groups, or salts thereof; more preferably a C₁-C₂₂ alkyl group, most preferably a C₂-C₁₈ unsubstituted alkyl group.

The crosslinking agent can be derived from an aldaric acid, aldarolactone, aldarodilactone, aldarolactone ester, aldaric acid monoester, aldaric acid diester, or aldaramides, or salts thereof. Preferably the crosslinking agent is derived from glucaric acid, galactaric acid, mannaric acid, xylaric acid or tartaric acid.

In another embodiment, the crosslinking agent is of the Formulae IX, X, XI, XII:

wherein A1 is selected from the group consisting of:

and salts thereof; and A2 is selected from the group consisting of —NH—R₅—NH— —NH—R₅—O— and —O—R₅—O—

and salts thereof. R₅ and R₇ are independently aliphatic or aromatic hydrocarbylene groups, linear or cyclic, optionally substituted with alkyl, aryl, hydroxy, amino, carbonyl, carboxyl, ester, amide, alkoxy, nitrile or halogen, or slats thereof, and optionally containing —O—, —Si(ZZ′)O—, —(C═O)— or —NZ— linkages, where Z and Z′ are independently hydrogen, alkyl, substituted alkyl, alkaryl, substituted alkaryl, aryl, or substituted aryl; and R₆ is hydrogen or a 1-22 carbon alkyl group.

Preferably, R₅ and R₇ are independently optionally substituted aliphatic carbon chains with optional —(NZ)- or —O— linkages, wherein Z is hydrogen, optionally substituted alkyl or optionally substituted aryl. More preferably, R₅ and R₇ are independently linear, cyclic, or branched alkylene groups of 1-10 carbon atoms, optionally substituted with —O— linkages, and optionally substituted with —NH₂ groups, or salts thereof.

Also preferably, R₇ is —[(CH₂)₁₋₂₁]—, —CH(CH₃)—, —CH(isopropyl)-, —CH(isobutyl)-, —CH(CH(CH₃)CH₂CH₃)—, —CH(CH₂OH)—, —CH(CH₂CH₂SCH₃)—, —CH(CH(OH)CH₃)—, —CH(CH₂C₆H₅)—, —CH(CH₂C₆H₄OH)—, —CH(CH₂CONH₂)—, or —CH(CH₂CH₂CONH₂)—;

and

R₅ is —[(CH₂)₂₋₂₂]—, —[(CH₂)₀₋₆(C₆H₁₀)(CH₂)₀₋₆]—, —[(CH₂)₀₋₆C₆H₄(CH₂)₀₋₆]—, —[CH₂CH₂(OCH₂CH₂)₁₋₂₁]—, —[CH₂CH(CH₃)[OCH₂CH(CH₃)]₁₋₂₁]—, —(CH₂CH₂NH)₁₋₂₂CH₂CH₂—, —[CH₂CH(CH₃)[OCH₂CH(CH₃)]_(x)(OCH₂CH₂)_(y)[OCH₂CH(CH₃)]_(z)]— wherein x+y+z=2-50, —[CH₂CH₂(OCH₂CH₂)_(x)[OCH₂CH(CH₃)]_(y)(OCH₂CH₂)_(z)]— wherein x+y+z=2-50, —[CH(CH₃)CH₂O]_(x)CH₂C(Z′)(CH₂[OCH₂CH(CH₃)]_(y)—)CH₂[OCH₂CH(CH₃)]_(z)—

wherein x+y+z=2-10 and Z′ is H, methyl or ethyl, —[CH(CH₃)CH₂O]_(x)CH₂CH([OCH₂CH(CH₃)]_(y)—)CH₂[OCH₂CH(CH₃)]_(z)— wherein x+y+z=3-100, or —CH₂CH₂CH₂CH₂[CH(NH₂)CONHCH₂CH₂CH₂CH₂]₀₋₁₀CH(COYR)— or salts thereof, wherein Y is O or NH, and R is a C₁-C₂₂ optionally substituted alkyl, aryl, or alkaryl.

Examples of polyoxaalkyleneamines that can be used include those based on Jeffamine® polyether amines (Huntsman LLC, Salt Lake City, Utah). Polytetramethylene glycols that can be used include those based on Terathane® polytetramethylene ether glycol (E. I. DuPont de Nemours, Wilmington, Del.).

In some embodiments, about 0.0005 to about 0.5 molar equivalents of crosslinking agent per reactive pendant group can be used in the process. Preferably, from about 0.005 to about 0.5 molar equivalents of crosslinking agent are used per reactive pendant group, and more preferably about 0.01 to 0.25 molar equivalents per reactive pendant group.

The processes can be run at any suitable temperature but preferably at about 20° C. to about 100° C. The processes can be carried out in a polymer melt, but are preferably carried out in the presence of a solvent. The choice of solvent is not critical provided the solvent is not detrimental to reactant or product. Preferred solvents include water, dimethylformamide, dimethylformamide LiCl, dimethylacetamide, dimethylacetamide LiCl, ethanol, and methanol.

The polymers described herein are suitable for use as hydrogels. Hydrogels (hydrated gels) are herein defined as materials that absorb large quantities of liquid, i.e., greater than 2 mass equivalents of liquid. They are usually water-swellable, three-dimensional networks of macromolecules held together by covalent or noncovalent crosslinks. When placed in aqueous solution, these networks swell to the extent allowed by the degree of crosslinking. Hydrogels are useful in a variety of applications, such as medical products, personal care formulations, exfoliants, humectants, surfactants, thickeners, anti-irritants, antimicrobials, lubricants, emulsifiers, delivery agents, coatings, and surfactants. The crosslinked polymers invention can be modified to produce a variety of desirable properties for particular applications.

EXAMPLES

Abbreviation Ingredient Name 1BrC16 1-bromohexadecane 4,9-DODDA 4,9-dioxa-1,12-dodecanediamine 9DA 1,9-diaminononane DMG dimethyl galactarate GA D-glucaric acid GDL D-glucaro-1,4:6,3-dilactone HMDA 1,6-hexanediamine JEFF Jeffamine ® JEFF EDR-148 Jeffamine ® (H₂NCH₂CH₂OCH₂CH₂OCH₂CH₂NH₂) JEFF EDR-192 Jeffamine ® (H₂NCH₂CH₂(OCH₂CH₂)₃NH₂) JEFF T5000 Jeffamine ® polyethertriamine JEFF T403 Jeffamine ® polypropyleneoxytriamine PAlAmHCl polyallylamine HCl (obtained from Polysciences, Inc., Warrington, PA)

Analyses

Unless otherwise specified, the analyses were performed as follows.

Inherent Viscosity (η_(inh))

Inherent viscosities were generally run as 0.5% solutions in either hexafluoroisopropanol (HFIP) or m-cresol at 30° C.

Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA)

DSC and TGA studies of all polymers were conducted on 5-10 mg samples run at 10° C./min under nitrogen. Sample temperatures spanned ranges beginning as low as −100° C. to as high as 300° C., depending on polymer character and stability. Samples were generally cooled after the first heat cycle and a second heat cycle was then conducted. Generally, polymer DSC results reported are second heat results to eliminate artifacts of thermal history variations.

Swell Factor

Into a pre-dried, tared, 150 mL coarse fritted filter funnel was added about 1 g of polymer. The stem of the funnel was sealed with a rubber stopper. The funnel was placed on a filter flask and about 100 mL of distilled water at about 22° C. is added to the funnel. The contents were stirred, if necessary, to fully disperse the water and polymer. The contents were then left undisturbed for 15 minutes. The rubber stopper was then removed from the stem of the funnel, and suction was applied to the funnel for 5 minutes. The stem and underside of the funnel were then rinsed with ethanol to remove any remaining water droplets and suction was then continued for an additional 5 minutes. Any remaining water droplets were wiped off the funnel with a paper towel. The funnel and contents were then weighed to determine the weight of water retained by the polymer.

$\begin{matrix} {{{Swell}\mspace{14mu}{factor}} = \frac{\begin{matrix} {\left( {{{total}\mspace{14mu}{{wt}.\mspace{14mu}{of}}\mspace{14mu}{wet}\mspace{14mu}{polymer}} + {funnel}} \right) -} \\ \left( {{{total}\mspace{14mu}{{wt}.\mspace{14mu}{of}}\mspace{14mu}{dry}\mspace{14mu}{polymer}} + {funnel}} \right) \end{matrix}}{{{wt}.\mspace{14mu}{of}}\mspace{14mu}{dry}\mspace{14mu}{polymer}}} \\ {= \frac{\left( {{wet}\mspace{14mu}{{wt}.\;{- {dry}}}\mspace{14mu}{{wt}.}} \right)}{{dry}\mspace{14mu}{{wt}.}}} \\ {= \frac{g\mspace{14mu}{water}\mspace{14mu}{retained}}{g\mspace{14mu}{polymer}}} \end{matrix}$

Solubility

Solubilities were generally determined using 0.01 g of test material in 10 mL of test solvent. The vials containing the samples were constantly agitated via a shaker tray at room temperature for anywhere between 24 hours and 4 weeks. Solubility was determined by visual inspection to determine sample homogeneity. Any variance in density gradient, or refractive index was taken as indicating insolubility. Samples deemed to be insoluble were shaken at room temperature for at least 1 week, and in many cases were shaken for 2 weeks or more. A wide range of common solvent types was generally used to allow a broad range of polarity and solvent parameters to come into play.

Film Properties

Film properties were determined on 0.25 in×2 in samples cut from larger films spread onto glass with a blade applicator. Generally, films had thicknesses of 5 mil or less. Film properties reported represent an average of at least five measurements for each sample.

The reactions depicted in the following Examples are meant to be illustrative only and not representative of exact structures.

Examples 1-28

Polymers were prepared by first dissolving polyallylamine hydrochloride of ˜60,000 molecular weight in water. To that solution was added enough sodium hydroxide to just neutralize the equivalent amount of ammonium hydrochloride functions as would be used by the added GDL. To the partially neutralized polyallylamine hydrochloride was added a water solution of GDL at room temperature. The reaction was substantially over in a matter of minutes. A representative polymerization with GDL is shown below.

The crosslinking was performed using various compounds as described below in a representative reaction with GDL. When another compound was used in the in the crosslinking reaction along with the GDL, such as 9DA, they were both added simultaneously. Into a 250-mL 3-necked round bottom flask equipped with a heating mantle, reflux condenser, nitrogen inlet, and overhead stirrer was added 20 mL of water, 2.80 g (0.030 equivalent, 60,000 MW) of polyallylamine HCl, and 0.26 g (0.0066 mol) of sodium hydroxide. This mixture was stirred at room temperature until a homogeneous solution was achieved (˜10 minutes). At this point, a homogeneous solution prepared from 10 mL of water and 0.57 g (0.0033 mol) of GDL was slowly poured at room temperature into the solution containing the polyallylamine HCl. Within 1 to 2 minutes, gel had formed. The gel was then allowed to stir for ˜2 hours at room temperature, after which time it was removed from the flask. The gel was then washed 3 times with 100 mL aliquots of methanol followed by THF. The gel was then dried in a vacuum oven at 80° C. to yield 2.79 g (89.1%) of a granular white hydrogel polymer. The results are shown in Table 1. The % crosslinking shown in Table 1 is a theoretical calculation of the % of total amine nitrogens (from the polyallylamine hydrochloride) tied up in the crosslinking process with the aldaric acid. The calculation was based on the total weight of polyallylamine hydrochloride used (molar equivalents of allylamine) and the total molar equivalents of the GDL added to the process. Total final crosslinking was not measured but is assumed since the polymer gelled and became insoluble, although NMR indicated that conversion was less than 100%.

When only 5-15% of the ammonium groups were allowed to react with GDL, a very viscous water solution resulted that could be cast into a film. The resulting films were brittle, but less so than the starting polyallylamine hydrochloride homopolymer. As more ammonium groups reacted with GDL, gels eventually formed. Highly swellable hydrogels (with swell ratios as high as 90) were readily formed when ˜22% of the ammonium hydrochloride equivalents were neutralized and GDL was added in an equivalent amount (˜11% since both ends of the molecule are assumed to react). The gels were optically clear and colorless. It is unknown as to how much of the GDL was fully incorporated into the polymer, but it does appear that an equilibrium was reached in the polymer as evidenced by hydrogel samples that had been kept in water for months without loosing viscosity. If hydrolysis fully destroys all of the initially formed amide bonds, the hydrogel would slowly lose viscosity and eventually fully dissolve.

The data in Tables 1 and 2 show some of the properties that can be obtained in the polymers by varying the ingredients used in making them.

TABLE 1 Solvent/ % Ex. Composition Catalyst Media Color Yield Inh Visc Inh Sol. Polym. Character Swell 1 PAlAmHCl/GDL (10:1) - 20% triethylamine water white — insol HFIP Powder 4.72 crosslinking 2 PAlAmHCl/GDL (8:1) - 25% triethylamine water white — insol HFIP powder - very brittle 12.27 crosslinking film 3 PAlAmHCl/GDL (8.7:1) - 23% triethylamine water white — insol HFIP powder - poor film 80.73 crosslinking 4 PAlAmHCl/GDL (5:1) - 40% triethylamine water off white 90.1 insol HFIP Powder 48 crosslinking 5 PAlAmHCl/GDL (9.1:1) - 22% triethylamine water white — insol HFIP powder - very brittle 28.1 crosslinking film 6 PAlAmHCl/GDL (9.1:1) - 22% sodium water white 89.1 insol HFIP Powder 89.5 crosslinking hydroxide 7 PAlAmHCl/GDL (9.1:1) - 22% calcium water white 84.7 insol HFIP Powder 88.5 crosslinking hydroxide 8 PAlAmHCl/GDL (9.1:1) - 22% calcium water white — insol HFIP powder - poor film, 6.36 crosslinking hydroxide very brittle 9 PAlAmHCl/GDL (9.1:1) - 22% calcium water white — insol HFIP powder - poor film, sol. in crosslinking hydroxide very brittle water 10 PAlAmHCl/(GDL/JEFF EDR- sodium water white 68.1 insol water powder - brittle, clear 71.3 148 (2:1)) - 20% crosslinking hydroxide film 11 PAlAmHCl/(GDL/JEFF EDR- sodium water white 92.9 insol water powder - brittle, clear 49 192 (2:1)) - 20% crosslinking hydroxide film 12 PAlAmHCl/(GDL/JEFF T5000 sodium water/ white 40   insol water Powder 40.1 (3:1)) - 10% crosslinking hydroxide ethanol 13 PAlAmHCl/(GDL/JEFF T5000 sodium water/ white 31.9 insol water Powder 8.04 (3:1)) - 20% crosslinking hydroxide ethanol 14 PAlAmHCl/(GDL/JEFF T5000 sodium water/ white 28.4 insol water powder - poor film sol. in (3:1)) - 5% crosslinking hydroxide ethanol water 15 PAlAmHCl/(GDL/JEFF T5000 sodium water/ white — insol water powder - poor, clear, sol. in (3:1)) - 1% crosslinking hydroxide ethanol brittle film water 16 PAlAmHCl/(GDL/JEFF T5000 sodium water/ white 61.6 insol water powder - very poor 11 (3:1)) - 3% crosslinking hydroxide ethanol film 17 PAlAmHCl/(GDL/JEFF T403 sodium water white 69.4 insol water powder - poor, brittle sol.in (3:1)) - 3% crosslinking hydroxide film water 18 PAlAmHCl/(GDL/JEFF T403 sodium water white 74.2 insol water powder - poor, very sol. in (3:1)) - 5% crosslinking hydroxide brittle film water 19 PAlAmHCl/(GDL/JEFF T403 sodium water white 83.9 insol water powder - poor, brittle 83.8 (3:1)) - 20% crosslinking hydroxide film 20 PAlAmHCl/(GDL/4,9-DODDA sodium water white 77.4 insol water powder - clear film, 78.6 (2:1)) - 20% crosslinking hydroxide slightly flexible, fair 21 PAlAmHCl/(GDL/4,9-DODDA sodium water light 77.2 insol water powder - very poor 26.7 (2:1)) - 25% crosslinking hydroxide yellow film 22 PAlAmHCl/(GDL/(9DA/4,9- sodium water white 60   — — Powder 31.1 DODDA) (2:0.5:0.5)) - 20% hydroxide crosslinking 23 PAlAmHCl/(GDL/9DA (2:1)) - sodium water white 63.6 — — Powder 23.7 20% crosslinking hydroxide 24 PAlAmHCl/(GDL/9DA (2:1)) - sodium water white — — — powder - fair film, 75.2 15% crosslinking hydroxide slightly flexible 25 PAlAmHCl/(GDL/4,9- sodium water tan — — — powder - poor, brittle 48.5 DODDA/9DA (2/0.5/0.5)) - 15% hydroxide film crosslinking 26 PAlAmHCl/(GDL/4,9-DODDA sodium water tan — — — powder - poor film 2 (1.33:1)) hydroxide 27 PAlAmHCl/(GDL/9DA (1.33:1)) sodium water off white — — — powder - poor film 1.29 hydroxide 28 PAlAmHCl/(GDL/9DA (2:1)) - sodium water light 82.9 — — Powder 0.65 100% crosslinking hydroxide yellow

TABLE 2 Ex. Composition Tg 1 (C) Tg 2 (C) Tg 3 (C) Tm 1 (C) ΔH (J/g) Tm 2 (C) d H (J/g) Tm 3 (C) d H (J/g) 1 PAlAmHCl/GDL (10:1) - — — — 180.9  — — — — — 20% crosslinking 2 PAlAmHCl/GDL (8:1) - 25% — — — 190.97 — — — — — crosslinking 3 PAlAmHCl/GDL (8.7:1) - — — — 191.23 7.544 — — — — 23% crosslinking 4 PAlAmHCl/GDL (5:1) - 40% — — — 192.38 17.99 — — — — crosslinking 5 PAlAmHCl/GDL (9.1:1) - — — — 196.63 5.076 — — — — 22% crosslinking 6 PAlAmHCl/GDL (9.1:1) - — — — 196.75 5.318 — — — — 22% crosslinking 7 PAlAmHCl/GDL (9.1:1) - — — — 251.32 15.99 — — — — 22% crosslinking 8 PAlAmHCl/GDL (9.1:1) - — — — 202.61 7.165 — — — — 22% crosslinking 9 PAlAmHCl/GDL (9.1:1) - — — — 165.56 1.245 — — — — 22% crosslinking 10 PAlAmHCl/(GDL/JEFF — — — 187   5.99 248.04 6.291 — — EDR-148 (2:1)) - 20% crosslinking 11 PAlAmHCl/(GDL/JEFF — — — — — — — — — EDR-192 (2:1)) - 20% crosslinking 12 PAlAmHCl/(GDL/JEFF — — — 188.45 1.008 251.86 4.542 — — T5000 (3:1)) - 10% crosslinking 13 PAlAmHCl/(GDL/JEFF — — — 251.88 7.862 — — — — T5000 (3:1)) - 20% crosslinking 14 PAlAmHCl/(GDL/JEFF — — — 220.09 2.666 — — — — T5000 (3:1)) - 5% crosslinking 15 PAlAmHCl/(GDL/JEFF 204.2 — — — — — — — — T5000 (3:1)) - 1% crosslinking 16 PAlAmHCl/(GDL/JEFF 102.6 215.5 — — — — — — — T5000 (3:1)) - 3% crosslinking 17 PAlAmHCl/(GDL/JEFF 224.4 — — — — — — — — T403 (3:1)) - 3% crosslinking 18 PAlAmHCl/(GDL/JEFF 170   232.3 — — — — — — — T403 (3:1)) - 5% crosslinking 19 PAlAmHCl/(GDL/JEFF 175.7 227.5 — — — — — — — T403 (3:1)) - 20% crosslinking 20 PAlAmHCl/(GDL/4,9- 168.8 234.4 204.7 1.281 — — — — DODDA (2:1)) - 20% crosslinking 21 PAlAmHCl/(GDL/4,9- 171   209.5 247.6 — — — — — — DODDA (2:1)) - 25% crosslinking 22 PAlAmHCl/(GDL/(9DA/4,9- 174.4 — — — — — — — — DODDA) (2:0.5:0.5)) - 20% crosslinking 23 PAlAmHCl/(GDL/9DA 174.9 — — — — — — — — (2:1)) - 20% crosslinking 24 PAlAmHCl/(GDL/9DA 168.7 — — — — — — — — (2:1)) - 15% crosslinking 25 PAlAmHCl/(GDL/4,9- 142.5 174.2 — 224.28 0.261 — — — — DODDA/9DA (2/0.5/0.5)) - 15% crosslinking 26 PAlAmHCl/(GDL/4,9-  45   216.6 — 103.33 177.97 23.69 188.41 16.3   DODDA (1.33:1)) 27 PAlAmHCl/(GDL/9DA  75.94 — — 152.48 12.17 165.25 31.69 195.55  9.072 (1.33:1)) 28 PAlAmHCl/(GDL/9DA (2:1)) - — — — 167.03 4.206 190.61 14.02 — — 100% crosslinking

TABLE 3 Tc 1 d H Tc Tdec Sol. Sol. Sol. Sol. Sol. Sol. Sol. Ex. Composition (C) (J/g) 2 (C) d H (J/g) (C) H2O MeOH Toluene DMSO DMAC THF CH2CL2 1 PAlAmHCl/GDL (10:1) - — — — — 200 sol. insol. insol. insol. insol. insol. insol. 20% crosslinking 2 PAlAmHCl/GDL (8:1) - 25% — — — — 200 insol. insol. insol. insol. insol. insol. insol. crosslinking 3 PAlAmHCl/GDL (8.7:1) - — — — — 225 insol. insol. insol. insol. insol. insol. insol. 23% crosslinking 4 PAlAmHCl/GDL (5:1) - 40% — — — — 225 insol. insol. insol. insol. insol. insol. insol. crosslinking 5 PAlAmHCl/GDL (9.1:1) - — — — — 200 insol. insol. insol. insol. insol. insol. insol. 22% crosslinking 6 PAlAmHCl/GDL (9.1:1) - — — — — 225 insol. insol. insol. insol. insol. insol. insol. 22% crosslinking 7 PAlAmHCl/GDL (9.1:1) - — — — — 220 insol. insol. insol. insol. insol. insol. insol. 22% crosslinking 8 PAlAmHCl/GDL (9.1:1) - — — — — 210 insol. insol. insol. insol. insol. insol. insol. 22% crosslinking 9 PAlAmHCl/GDL (9.1:1) - — — — — 210 sol. insol. insol. insol. insol. insol. insol. 22% crosslinking 10 PAlAmHCl/(GDL/JEFF — — — — 210 — — — — — — — EDR-148 (2:1)) - 20% crosslinking 11 PAlAmHCl/(GDL/JEFF 223.41 9.953 — — 210 insol. insol. insol. insol. insol. insol. insol. EDR-192 (2:1)) - 20% crosslinking 12 PAlAmHCl/(GDL/JEFF — — — — 200 insol. insol. insol. insol. insol. insol. insol. T5000 (3:1)) - 10% crosslinking 13 PAlAmHCl/(GDL/JEFF — — — — 210 insol. insol. insol. insol. insol. insol. insol. T5000 (3:1)) - 20% crosslinking 14 PAlAmHCl/(GDL/JEFF — — — — 225 insol. insol. insol. insol. insol. insol. insol. T5000 (3:1)) - 5% crosslinking 15 PAlAmHCl/(GDL/JEFF — — — — 250 sol. insol. insol. insol. insol. insol. insol. T5000 (3:1)) - 1% crosslinking 16 PAlAmHCl/(GDL/JEFF — — — — 235 insol. insol. insol. insol. insol. insol. insol. T5000 (3:1)) - 3% crosslinking 17 PAlAmHCl/(GDL/JEFF — — — — 240 sol. insol. insol. insol. insol. insol. insol. T403 (3:1)) - 3% crosslinking 18 PAlAmHCl/(GDL/JEFF — — — — 240 sol. insol. insol. insol. insol. insol. insol. T403 (3:1)) - 5% crosslinking 19 PAlAmHCl/(GDL/JEFF — — — — 225 insol. insol. insol. insol. insol. insol. insol. T403 (3:1)) - 20% crosslinking 20 PAlAmHCl/(GDL/4,9- — — — — 200 insol. insol. insol. insol. insol. insol. insol. DODDA (2:1)) - 20% crosslinking 21 PAlAmHCl/(GDL/4,9- 284.77 1.116 — — 200 insol. insol. insol. insol. insol. insol. insol. DODDA (2:1)) - 25% crosslinking 22 PAlAmHCl/(GDL/(9DA/4,9- — — — — 225 insol. insol. insol. insol. insol. insol. insol. DODDA) (2:0.5:0.5)) - 20% crosslinking 23 PAlAmHCl/(GDL/9DA — — — — 225 insol. insol. insol. insol. insol. insol. insol. (2:1)) - 20% crosslinking 24 PAlAmHCl/(GDL/9DA — — — — 225 insol. insol. insol. insol. insol. insol. insol. (2:1)) - 15% crosslinking 25 PAlAmHCl/(GDL/4,9- — — — — 175 insol. insol. insol. insol. insol. insol. insol. DODDA/9DA (2/0.5/0.5)) - 15% crosslinking 26 PAlAmHCl/(GDL/4,9- — — — — 150 insol. insol. insol. insol. insol. insol. insol. DODDA (1.33:1)) 27 PAlAmHCl/(GDL/9DA — — — — 150 insol. insol. insol. insol. insol. insol. insol. (1.33:1)) 28 PAlAmHCl/(GDL/9DA (2:1)) - — — — — 150 — — — — — — — 100% crosslinking

Example 29 Synthesis of Modified Polyallylamine Crosslinked with GDL

Into a 2000-mL 3-necked flask equipped with a heating mantle, reflux condenser, nitrogen inlet, and overhead stirrer was added 525 mL of water, 70 g of polyallylamine hydrochloride (0.749 mole equivalent of amine), and 2.24 g (0.056 mol) of sodium hydroxide. After these ingredients dissolved, 17.08 g (0.056 mol) of 1-bromohexadecane was added. The reaction mixture was heated at reflux for 5 hours. Afterward, the reaction mixture was cooled to room temperature and stirred overnight. An additional 5.60 g (0.140 mol) of sodium hydroxide was added to the mixture. After the sodium hydroxide dissolved, 12.18 g (0.070 mol) of GDL dissolved in 175 mL of water was added to the reaction mixture. Almost immediately a gel formed. The gelled mixture was then gently heated at 50° C. for about 7 hours. The gel was filtered, washed 3× with methanol, and then washed 3× with THF. It was then put into a vacuum oven set at 80° C. for at 24 hours to dry the polymer. The pale yellow polymer (58.85 g, 60.5%) exhibited a swell ratio of 7.9.

Example 30A Synthesis of Polyallylamine Crosslinked with Diethyl Tartrate

The preparation was conducted under nitrogen atmosphere with oven-dried glassware. Polyallylamine hydrochloride (MW ca. 60,000, 0.876 g, 9.36 mmol) was weighed into a 20-mL scintillation vial equipped with a magnetic stirbar, and water (2 mL) was added. Dropwise addition of an aqueous solution (1.0 mL) of sodium hydroxide (0.113 g, 2.83 mmol) to the solution resulted in a viscous solution. A solution of diethyl L-tartrate (0.240 mL, 1.40 mmol) in water (1.0 mL) was added and the resulting solution was stirred at ambient temperatures for 38 hours. The gelled reaction mixture was washed with methanol (160 mL) to remove sodium chloride. Vacuum-drying gave a white solid (0.86 g, 93% yield) that exhibited a swell ratio of 112.6 (determined after swollen gel was subjected to 6 hours of dynamic suction followed by ˜28 hours of static suction).

Example 30B Synthesis of Polyallylamine Crosslinked with Diethyl Tartrate

Poly(allylamine hydrochloride), M_(w) 60,000 (42.04 g, 0.4493 mole of amine groups) was dissolved overnight in 155 mL of water in a 3-neck 500-mL round-bottom flask equipped with a magnetic stir bar. A solution of 5.392 g (0.1348 mole) of sodium hydroxide in 25 mL of water was added dropwise over a period of 10 minutes, using 2 mL of water to complete the transfer. To the resulting pale yellow syrup was added with stirring a solution of 13.897 g (67.40 mmoles) of diethyl L-tartrate in 10 mL of water, using 2 mL of water to complete the transfer. The reaction was allowed to proceed for 4 days, during which the mixture gelled and the magnetic stir bar seized. The reaction mixture was combined with 250 mL of methanol to precipitate out the product. The resulting gummy solid was separated from the liquid and triturated in a blender with 8 successive 250-mL portions of methanol, decanting the methanol each time. The resulting solid was ground and dried under vacuum to give 38.47 g (86% yield) of hydrogel that exhibited a swell factor of 224.

Example 31 Synthesis of Polyallylamine Crosslinked with GDL

The preparation was conducted in a drybox with oven-dried glassware. Polyallylamine hydrochloride (MW ca. 60,000, 6.88 g, 73.5 mmol) was weighed into a 500-mL round-bottom flask equipped with a magnetic stirbar. Methanol (285 mL) was added and the solution was treated with neat triethylamine (12.3 mL, 88.3 mmol) followed by dropwise addition of a solution of GDL (0.13 g, 0.74 mmol) in methanol (10 mL). The resulting solution was stirred at ambient temperature for four days. Most of the reaction solvent was decanted, and the remaining reaction mixture was filtered and vacuum-dried to give a white solid (1.00 g, 23% yield) that exhibited a swell ratio of 22.8. When the swell test was repeated, allowing 19 hours for the gel to swell followed by 2 hours of dynamic suction and 9 hours of static suction, the swell ratio was 22.4. After 14 hours' exposure to ambient atmosphere, the sample retained 19.9 times its own weight in water.

Example 32A Synthesis of Polyallylamine Crosslinked with N,N′-Bis(ethoxycarbonylmethyl)-D-glucaramide

Preparation was conducted in a drybox with oven-dried glassware. Polyallylamine hydrochloride (MW ca. 60,000, 6.55 g, 70.0 mmol) was weighed into a 500-mL round-bottom flask equipped with a magnetic stirbar. Methanol (270 mL) was added and the solution was treated with neat triethylamine (11.7 mL, 84.0 mmol) followed by a slurry of N,N′-bis(methoxycarbonylmethyl)-D-glucaramide (0.25 g, 0.69 mmol) in methanol (20 mL). The resulting solution was stirred at ambient temperature for four days. The reaction solvent was removed under vacuum, and the oily solid was washed repeatedly with methanol (180 mL). Addition of pentane (50 mL) to a methanol slurry (ca. 20 mL volume) produced a solid that was filtered and then vacuum-dried to give a white solid (2.39 g, 57% yield) that exhibited a swell ratio (after 29 minutes of suction) of 62.8. When the swell test was repeated, allowing 16 hours for the gel to swell followed by 34 minutes of suction, the swell ratio was 118.9. After 23 hours' exposure to ambient atmosphere, the sample retained 108.6 times its own weight in water.

Example 32B Synthesis of Polyallylamine Crosslinked with N,N′-Bis(ethoxycarbonylmethyl)-D-glucaramide

To 23.03 g (0.2463 mole of amine groups) of poly(allylamine hydrochloride), M_(w) 60,000, in 950 mL of dry methanol in a 2-L round-bottom flask under nitrogen were added 41.2 mL (0.296 mole) of triethylamine over 30 minutes. A slurry of N,N′-bis(ethoxycarbonylmethyl)-D-glucaramide in a total of 65 mL of dry methanol was then added. The mixture was stirred at ambient temperature for 5 days and then concentrated under reduced pressure to about 150 mL. The resulting solid was separated from the methanol, washed repeatedly with methanol and then dried under vacuum to give 12.92 g (88% yield) of hydrogel that exhibited a swell factor of 125.

Example 33

Polyallylamine hydrochloride (MW ca. 60,000, 2.84 g, 30.4 mmol) was weighed into 100-mL round-bottom flask equipped with a magnetic stirbar. Water (16 mL) was added and the solution was treated with an aqueous (4 mL) solution of sodium hydroxide (0.27 g, 6.67 mmol) followed by a solution of GDL (0.58 g, 3.34 mmol) in water (10 mL). The reaction solution was stirred overnight at ambient temperature resulting in a gel-like mixture. The gel was washed with four 50-mL portions of methanol and then vacuum-dried to give a white solid (2.26 g, 69% yield) that exhibited a swell ratio (after 2 hours of suction) of 186.5. After 3 additional days' exposure to static suction, the sample retained 67.9 times its own weight in water. When the swell test was repeated with the same sample, allowing 5 hours for the gel to swell followed by 2 hours of dynamic suction and 24 hours of static suction, the swell ratio was 206.0. After 3 and 8 days' additional exposure to static suction, the sample retained 173.8 and 65.5 times its own weight in water, respectively.

Example 34

Preparation was conducted under nitrogen atmosphere with oven-dried glassware. Polyallylamine hydrochloride (MW ca. 60,000, 1.01 g, 10.8 mmol) was weighed into a 20-mL scintillation vial equipped with a magnetic stirbar, and water (2 mL) was added. Dropwise addition to the slurry of an aqueous solution (1.0 mL) of sodium hydroxide (0.033 g, 0.83 mmol) resulted in a viscous solution. A solution of N,N′-bis(methoxycarbonylmethyl)-D-glucaramide (0.14 g, 0.41 mmol) in water (1.5 mL) was added, and the resulting solution was stirred at ambient temperature for 45 hours. Solvent was removed under vacuum from the gelled reaction mixture, and the solid was washed with methanol (125 mL) to remove sodium chloride. Vacuum-drying gave a white solid (0.98 g, 89% yield) that exhibited a swell ratio (after 5 minutes of dynamic suction and 45 minutes of static suction) of 105.8. After 2 days' exposure to ambient atmosphere, the sample retained 96.5 times its own weight in water. When the swell test was repeated with the same sample, allowing 4.5 hours for the gel to swell followed by 5 hours of dynamic suction and 14 hours of static suction, the swell ratio was 197.6. After 6 days' exposure to ambient atmosphere, the sample retained 167.8 times its own weight in water.

Example 35

Polyethyleneimine (M_(n)=ca. 10,000, M_(w)=ca. 25,000, Aldrich 408727, 0.74 g, 17.2 mmol) was weighed into a 20-mL scintillation vial equipped with a magnetic stirbar, and methanol (4.5 mL) was added. Concentrated hydrochloric acid (0.72 mL, 8.65 mmol) was added to the reaction solution dropwise over ca. one minute and the mixture was stirred at ambient temperature for 3 hours. A solution of GDL (0.15 g, 0.862 mmol) in methanol (1 mL) was added dropwise over ca. one minute to the reaction solution. The reaction mixture began to gel after 3 hours, but stirring was continued for 24 hours. The solvent was removed under vacuum and the solid was vacuum-dried to give a yellow solid (ca. 0.2 g) that exhibited a swell ratio (after 1 hour of static suction) of 24.1. After 5 days' exposure to ambient atmosphere, the sample retained 9.2 times its own weight in water. When the swell test was repeated with the same sample, allowing 7.5 hours for the gel to swell followed by 35 minutes of dynamic suction, the swell ratio was 36.6. After 1 day's exposure to ambient atmosphere, the sample retained 34.2 times its own weight in water.

Example 36

Polyethyleneimine (M_(n)=ca. 10,000, M_(w)=ca. 25,000, Aldrich 408727, 0.67 g, 15.6 mmol) was weighed into a 20-mL scintillation vial equipped with a magnetic stirbar, and water (2.5 mL) was added. Concentrated hydrochloric acid (0.65 mL) was added dropwise to the solution followed by solid N,N′-bis(methoxycarbonylmethyl)-D-glucaramide (0.14 g, 0.39 mmol) and water (1 mL). The reaction solution was stirred for 5 days at ambient temperature. The solvent was then removed under vacuum, and the solid was vacuum-dried to give a colorless solid that exhibited a swell ratio (after 50 minutes of dynamic suction and 15 minutes of static suction) of 17.6. When the swell test was repeated with the same sample, allowing 15 hours for the gel to swell followed by 2.25 hours of suction, the swell ratio was 25.5. After five days' exposure to ambient atmosphere, the sample retained 22.8 times its own weight in water.

Example 37 Biocidal Activity of Crosslinked Hydrogels

Antimicrobial activity was determined by a standard micro-shake flask test. Bacterial cultures were inoculated into TSB (Trypticase Soy Broth) and incubated at 37° C. overnight for 20±2 hours. The following day, the concentration of bacteria was adjusted to ˜1.0×10⁵ cfu/mL (cfu=colony forming unit) by dilution with 0.6 mM phosphate buffer. Diluted bacterial culture (2.5 mL) was then transferred into culture plate wells containing 2.5 mL of hydrogel (˜50 mg of solid dispersed in 2.5 mL of 0.6 mM phosphate buffer) or just 2.5 mL of 0.6 mM phosphate buffer (control). The culture plates were incubated at room temperature on a platform shaker with constant shaking motion. Three 100-μL aliquots were periodically removed from each well and serially diluted with 0.6 mM phosphate buffer. Undiluted and diluted samples from each well were plated onto duplicate TSA (trypticase soy agar) plates, and incubated at 37° C. for 20±2 hrs. After incubation, the number of bacterial colonies on each plate was counted using a Q-count instrument or equivalent counting method. The colony count was averaged and normalized by correcting for the dilution factor and reported as the number of colony forming units (cfu) per mL. Log reduction (log rdxn)=(mean log₁₀ density of microbes in flasks of untreated control samples)−(mean log₁₀ density of microbes in flasks of treated samples).

Microbes tested were Escherichia coli, Pseudomonas aeruginosa, Stapphylococcus aureus, and Candida albicans.

Three hydrogel samples were tested for antimicrobial activity: Sample A was prepared as in Example 29. Sample B was prepared as in Example 30A. Sample C was prepared as in Example 31. Results are in Table 4.

TABLE 4 Biocidal Activity of Crosslinked Hydrogels sample inoculum (control) A B C microbe t, h wt % log cfu log cfu log rdxn log cfu log rdxn log cfu log rdxn E. coli 4 1.0 4.86 1.37 3.49 0.00 4.86 0.00 4.86 0.50 4.86 1.73 3.13 0.00 4.86 0.00 4.86 0.25 4.86 1.70 3.16 0.00 4.86 0.00 4.86 0.10 4.86 2.22 2.64 0.00 4.86 0.00 4.86 24 1.0 4.86 0.00 4.86 0.50 4.86 0.00 4.86 0.25 4.86 0.00 4.86 0.10 4.86 0.00 4.86 P. aeruginosa 4 1.0 4.86 0.00 4.86 0.00 4.86 0.00 4.86 0.50 4.86 0.00 4.86 0.00 4.86 0.00 4.86 0.25 4.86 0.00 4.86 0.00 4.86 0.00 4.86 0.10 4.86 0.00 4.86 0.00 4.86 0.00 4.86 S. aureus 4 1.0 4.66 3.94 0.72 0.00 4.66 0.00 4.66 0.50 4.66 3.92 0.74 0.00 4.66 0.00 4.66 0.25 4.66 3.51 1.15 0.00 4.66 0.00 4.66 0.10 4.66 3.47 1.19 0.00 4.66 0.00 4.66 24 1.0 4.66 2.40 2.26 0.50 4.66 1.37 3.29 0.25 4.66 1.18 3.49 0.10 4.66 1.67 2.99 C. albicans 4 1.0 5.09 0.00 5.09 0.00 5.09 0.00 5.09 0.50 5.09 0.00 5.09 0.00 5.09 0.00 5.09 0.25 5.09 0.00 5.09 0.00 5.09 0.00 5.09 0.10 5.09 1.92 3.17 0.00 5.09 0.00 5.09

Example 38 Emulsion Prepared Using Hydrogel Prepared from Polyallylamine HCl, GDL, and Jeffamine® EDR-192

A crosslinked hydrogel was prepared in the following manner: 28.0 g (0.30 equiv) of polyallylamine hydrochloride was dissolved in 200 mL of water along with 2.4 g (0.06 mol) of sodium hydroxide. To that solution was added a solution of 5.2 g (0.030 mol) of GDL and 2.9 g (0.015 mol) of Jeffamine® EDR-192 dissolved in 100 mL of water. The mixture was then heated to 50° C. Within 1 hour, a gelled product had formed. The gel was left to “cure” overnight at room temperature. It was then filtered and washed 3 times with MeOH/THF. The remaining polymer was then dried in a vacuum oven at 80° C. to yield 20.63 g (61%) of a white granular material. The polymer exhibited a swell ratio of 81.

An emulsion was prepared using 2.0 g of the polymer prepared above, 17.0 g of octyl palmitate, and 148 mL of water. These ingredients were added to a 250-mL beaker and emulsified using a Silverson Lab Mixer equipped with a rotor-stator square-holed blade running at 5,000 rpm for 5 min. A thick, creamy white emulsion was prepared. After 8 months' storage in a jar at room temperature, separation of the emulsion was negligible.

Example 39 Preparation of Crosslinked Polymer using Poly(methacryloyl chloride), GDL, and Ethylenediamine

Into a 250-mL 3-necked round-bottom flask equipped with a heating mantle, reflux condenser, nitrogen inlet, and overhead stirrer was added a 25 mL of dioxane containing 6.25 g (0.598 equivalent) of poly(methacryloyl chloride) (Polysciences, Inc., Warrington, Pa.). To this solution was added 3.5 g (0.0150 mol) of N,N′-bis(2-aminoethyl)-D-glucaramide (prepared by reacting 10 equivalents of ethylenediamine with GDL in DMAC at 50° C. and isolating the product as a white precipitate). The mixture was stirred and heated at 50° C. over a period of 21 hours. During this time, a slight color change from brown to yellow was noted; however, it did not appear that the diaminodiamide was ever fully solubilized in the dioxane solvent. The resulting product was poured into THF, filtered, and washed 3 times with THF to yield 2.65 g (27%) of a light tan solid material; Tg₁ 49.67° C.; Tg₂ 64.14° C.; T_(dec) 175° C.-onset; η_(inh) (HFIP) insol.

Example 40 Synthesis of Chitosan Crosslinked with GDL

Chitosan (Primex TM-656, MW ca. 79,000, 95% deacetylated, 0.79 g, 4.90 mmol) was weighed into a 20-mL scintillation vial equipped with a magnetic stirbar. Water (11.5 mL) was added, and the mixture was stirred for 15 minutes at ambient temperature. A solution of hydrochloric acid (37%, 0.29 mL, 3.45 mmol) in water (1.5 mL) was added dropwise, and the resulting viscous light yellow mixture was stirred for 15 minutes at ambient temperature. A freshly prepared solution of GDL (0.09 g, 5.40 mmol) in water (1.5 mL) was added dropwise, and the reaction mixture was stirred for 38 hours at ambient temperature, resulting in a tan-colored homogeneous gel-like mixture. Approximately 5 mL of the solvent was removed under vacuum and the reaction mixture was transferred to a round-bottom flask with 15 mL of tetrahydrofuran. The resulting precipitate was washed with four 30-mL portions of tetrahydrofuran then vacuum-dried to give a white solid (0.75 g) that had a swell ratio of 3. 

What is claimed is:
 1. A process for forming a hydrogel polymer comprising the step: contacting a crosslinking agent with a substrate polymer at a temperature of from about 20° C. to about 100° C. to form a crosslinked hydrogel polymer; wherein the crosslinking agent is of Formula VI:

wherein the crosslinking agent forms a covalent crosslink with the substrate polymer after contacting the polymer at a temperature in the above range, and wherein the substrate polymer comprises reactive pendant groups attached to the polymeric backbone, wherein the substrate polymer is an amine group-containing polymer.
 2. The process of claim 1 wherein less than 100% of the amine groups are derivatized to make the derivatized amine groups unreactive to the crosslinking agent, wherein the derivatization is performed either before, during or after contact of the crosslinker with the polymer substrate.
 3. The process of claim 1 wherein the amine groups are derivatized before the contact of the crosslinker with the polymer substrate.
 4. The process of claim 1 wherein the amine groups are derivatized to contain an aliphatic carbon chain optionally substituted with —(NZ)— or —O— linkages, where Z is selected from the group consisting of hydrogen, optionally substituted alkyl and optionally substituted aryl.
 5. The process of claim 1 wherein the amine groups are derivatized to contain a linear or branched alkyl group of 1-22 carbon atoms, optionally substituted with —O— linkages, —NH₂, halogen, hydroxyl, or carbonyl groups, or salts thereof.
 6. The process of claim 1 wherein up to about 50% of the amine groups are derivatized.
 7. The process of claim 1 wherein up to about 20% of the amine groups are derivatized.
 8. The process of claim 1 wherein the crosslinking agent is derived from an aldaric acid, aldarolactone, aldarodilactone, aldarolactone ester, aldaric acid monoester, aldaric acid diester, or aldaramide, or salts thereof.
 9. The process of claim 1 wherein the crosslinking agent is derived from glucaric acid or mannaric acid.
 10. The process of claim 1 wherein about 0.0005 to about 0.5 molar equivalents of crosslinking agent are used per amine group.
 11. The process of claim 1 wherein about 0.005 to about 0.5 molar equivalents of crosslinking agent are used per amine group.
 12. The process of claim 1 wherein the substrate polymer is selected from polyallylamine, branched polyethyleneimine, or salts thereof. 